<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Promise关键问题 - Promise then方法的返回结果特点</title>
</head>
<body>
    <script>
        let p = new Promise((resolve, reject) => {
            resolve('ok');
        });
        //执行 then 方法
        let result = p.then(value => {
            // console.log(value);
            //1. 抛出错误
            // throw '出了问题';
            //2. 返回结果是非 Promise 类型的对象
            // return 521;
            //3. 返回结果是 Promise 对象
            // return new Promise((resolve, reject) => {
            //     // resolve('success');
            //     reject('error');
            // });
        }, reason => {
            console.warn(reason);
        });

        console.log(result);
    </script>
</body>
</html>